Two troubleshooters handle service calls for 10 machines. The average time between service requirements is 18 days, and service time averages 2 days. Assume exponential distributions. While running, each machine can produce 1500 pieces per day. Determine:
A) the percentage of time troubleshooters are idle
B) each machine's net productivity
C) If troubleshooters represent a cost of $150 per day, and machine downtime cost is $600 per day, would another troubleshooter be justified ? Explain.